Method for manufacturing refined methionine

Abstract

The object of the present invention is to provide a process for producing refined methionine in which the loss of methionine due to washing is reduced. The present invention relates to a process for producing refined methionine from crude methionine, comprising a step of washing crude methionine with the use of a wash water containing methionine.

1 . A process for producing refined methionine from crude methionine, comprising a step of washing crude methionine with the use of a wash water containing methionine. 
     
     
         2 . The process according to  claim 1 , wherein the concentration of methionine in the wash water is 1.0% by weight or higher. 
     
     
         3 . The process according to  claim 1 , wherein the wash water after being used for washing crude methionine is recovered and reused. 
     
     
         4 . The process according to  claim 3 , wherein washing of crude methionine is performed with the use of an additional wash water together with the reuse of a part of the wash water after being used for washing crude methionine. 
     
     
         5 . The process according to  claim 4 , wherein washing of crude methionine is performed by washing with the reused wash water, followed by the washing with the additional wash water. 
     
     
         6 . The process according to  claim 4 , wherein the additional wash water contains methionine. 
     
     
         7 . The process according to  claim 6 , wherein the concentration of methionine in the additional wash water is 2.0% by weight or higher. 
     
     
         8 . The process according to  claim 6 , wherein the additional wash water is substantially free from alkali. 
     
     
         9 . The process according to  claim 6 , further comprising a step of drying refined methionine, wherein the additional wash water is prepared by dissolving dried and refined methionine obtained in the step in pure water.